Technical

Gas safety on boats and leisure craft

Gas safety on boats is a specialist but important area for those gas engineers who work within the field. Here, Gas Safe Register Technical Officer David Tickle gives an overview of the standards and outlines the guidance on safety, flues, tightness testing and regulators.

The standards that generally apply to leisure craft and narrowboats used on canals and inland waterways in the UK are BS EN ISO 10239:2017(1) , which applies to LPG systems on small craft and PD 54823: 2016(2), which covers the design, commissioning and maintenance of LPG systems.

The maximum length of a narrowboat in the UK is 70ft (21.95m), and so the scope of the standards applies to leisure craft up 24m long. The principles and guidance can also be applied to a domestic houseboat longer than 24m that is permanently moored or used for partial navigation of a river such as the Thames or Norfolk waterways.

Tightness testing

New installations: Any new pipework – including any additions to an existing installation – is required to be tested initially using air as the test medium at a pressure of three times the normal working pressure. For propane, this would be 111mbar. This is a similar approach to carrying out a strength test in commercial installation testing procedures. Ongoing maintenance: Testing procedures using LPG should be used in the following circumstances: • Whenever work is carried out that may affect gas tightness • If a gas escape is suspected • Before re-establishing an existing gas supply. Bubble testers/gauges: Boats, yachts and any other vessel manufactured after August 2008 must incorporate a simple means of tightness testing into the LPG system before the installation is used (for example, after the exchange of cylinders). This could be a pressure gauge or a bubble tester. For existing vessels manufactured before August 2008, the installation of a bubble tester is down to the vessel owner’s personal choice.

Note: Gas Safe Register inspectors carry out a tightness test on installations in line with the relevant standards using a pressure gauge.

Cylinder storage

LPG cylinders – whether full or empty – pressure regulation devices and safety devices must be stored in cylinder lockers or housing, and secured to prevent movement that is expected in the course of marine service.

The craft and any such storage areas shall be designed to allow any escaping gas to drain/vent at a low level outside the craft, noting that gas is heavier than air.

There should be no potential sources of ignition in a storage compartment or locker and any electrical devices must have ignition protection in accordance with ISO 8846(3) .

Regulators and OPSO control

The regulator to be fitted inside the locker must be suitable for its application and able to deliver the correct pressure for the connected appliances. Boats, yachts and other vessels also require an over-pressure shut-off (OPSO) device to be installed to prevent uncontrolled pressure increase in the low-pressure side of the LPG system. Note: Most leisure craft are used on inland waterways in freshwater

Gas safety on boats and leisure craft

and most existing regulators/ OPSO devices are suitable. However, the engineer should confirm with the regulator or OPSO manufacturer that they are suitable for the environment in which they will be used. Not all devices are suitable for marine use, and salt water can affect their safe operation. Suitability for purpose should also be considered and checked for appliances and flexible pipework.

Pipework materials

Only solid drawn copper or drawn stainless steel shall be used for rigid pipework supply lines.

Jointing methods shall be metallic in construction: they can be brazed, hard-soldered, cutting ring-type fittings, compression fittings or manufacturer-specified fittings, such as pliable corrugated stainless-steel tube fittings.

Hoses and hose lines

The materials must be suitable for LPG and able to withstand the stresses and exposures of a marine environment. • Hoses shall be kept to a minimum practical length and shall not be routed through an engine compartment. • Hoses shall have permanently attached end fittings. • They shall be a continuous length and not be subjected to tension or kinking under normal use. • Hoses used for an LPG supply line shall have no joints from within the cylinder compartment to the appliance, or accessible isolation valve located near the appliance – except where metallic supply piping is connected to flexible hose connecting a moveable appliance such as a gimballed stove.

Shut-off valves

Each LPG system shall be equipped with a manually operated main shut-off valve located in the high-pressure side of the installation. This valve may be the cylinder valve or incorporated in the pressure regulation device.

A dual-cylinder installation shall be fitted with a manual or auto changeover device and fitted with non-return valves. These are in addition to the cylinder isolation valves.

A shut-off valve shall be installed in the low-pressure supply pipework to each appliance. If there is only one appliance fitted, the cylinder valve may be used for this function if it is located near the appliance. A remotely operable solenoid valve located in the cylinder housing is also This article is an overview of the relevant gas standards and available information. It is not exhaustive and you can find more information in Technical Bulletin 124: LPG on boats, yachts and other vessels – Update on Standards, gas tightness testing, bubble testers & pressure gauges, regulators and overpressure control.

You can read and download all Technical Bulletins by logging into your online account at

www.GasSafeRegister. co.uk/sign-in

PD 54823 and BS EN ISO 10239 are available as part of Gas Safe Register’s standards subscription facility – you can find out more by logging into your online account.

Gas safety on boats and leisure craft continued

acceptable provided that the valve can be operated from within the vicinity of the appliance.

The solenoid can be fitted to the high or low-pressure side of the installation. The solenoid shall be closed automatically in the event of electrical actuating energy failure or loss.

Appliances

Only appliances suitable and specified for use in a marine environment shall be installed. If the appliances are used or second-hand, they must be in a safe working condition and fit for purpose, and the manufacturer’s installation instructions must be available.

They shall be installed in accordance with the appliance manufacturer’s instructions and fixed to the craft to prevent undue stress on any pipework connecting the appliance.

All appliances must be equipped with a flame supervision device and clearly labelled to indicate the type of gas on which is it is designed to operate.

Ducts and flues for air intake and combustion product discharge

Flue components and ductwork shall be installed in accordance with the appliance manufacturer’s installation instructions.

Flues shall be sized and routed

Which standards apply?

In the hierarchy of standards, BS EN ISO 10239 is the one that is referenced most frequently. The prefix BS EN means it is the UK version, written in English, of a European harmonised standard; while BS EN ISO is an international standard that has been adopted by Europe as a European standard. A company manufacturing a boat or craft to sell abroad would need to comply with this standard as a minimum.

When an international standard is written, it must take in the views of an international panel of members from around the world. Sometimes there are compromises and differences from what you might expect to see when compared with other UK gas standards.

British boat builders will often refer to PD 54823:2016, which is controlled and maintained by BSI, as well as BS EN ISO 10239. PD 54823:2016 is a guidance document written to complement and reflect the requirements of BS EN ISO 10239. It mirrors the minimum requirements of the international standard and expands on the level of detail about how work should be carried out.

to ensure complete discharge of the products of combustion outside the vessel. Areas to be avoided are below canopies or areas that can be obstructed by an accumulation of water.

The flue system shall not have any dampers fitted and must not terminate within 500mm of any refuelling point, breather vent from the fuel tank or fuel system, or within 300mm of an opening window, door, port or ventilation grill.

The flue terminal shall be of substantial construction and fitted with a guard.

Owner’s manual

The leisure craft/boat manufacturer shall provide an owner’s manual and will include with it instructions for use of the LPG system, any relevant instructions for the appliances, safety advice, guidance and safety check requirements. ■

Boat Safety Scheme

Being a member of the Boat Safety Scheme permits the engineer to complete work on a leisure craft or boat that does not come under the Gas Safety (Installation & Use Regulations) (GSIUR) 1998, such as a leisure craft or boat that is used for personal use only. If the boat is hired out, used as a time share, shared ownership or a floating business such as cafes or shops, these fall within the scope of GSIUR. This requires that anyone contracted to work on the LPG system on a vessel in scope must be competent in LPG on boats and Gas Safe registered.

Because the definition of work covers the removal and replacement of a gas test point screw, the scope of GSIUR includes carrying out an LPG tightness test. Therefore, on a leisure craft or boat in scope of GSIUR, examiners who are not Gas Safe registered can only confirm gas tightness using one of the following methods: • Using a bubble leak detector, where fitted and correctly located, or • Observing a tightness test carried out by an

LPG boats-qualified Gas Safe engineer.

Note: All other types of work, such as adding or replacing an appliance, require the engineer to be Gas Safe registered and competent in LPG on boats.

Bibliography

(1) BS EN ISO 10239:2017 – Small craft: Liquified petroleum gas (LPG) Systems (2) PD 54823:2016 – Guidance for the design, commissioning and maintenance of LPG systems in small craft (3) ISO 8846:1990 – Small craft – Electrical devices — Protection against ignition of surrounding flammable gases